Direct drive for a subscriber line differential ringing signal
US7181003B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 2003 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | Apr 15, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method of generating a subscriber line ringing signal includes the step of applying a time-varying waveform W(t) to the tip line while maintaining the ring line at a pre-determined supply level for a duration T/2. The time-varying waveform is subsequently applied to the ring line while maintaining the tip line at the pre-determined supply level for the duration T/2. A subscriber line interface circuit apparatus includes a power supply providing a time-varying supply level, W(t). A signal processor controls a linefeed driver to alternately couple W(t) to one of the tip and ring lines while coupling an alternate supply level to the other of the tip and ring lines for a duration T/2. In various embodiments, the resulting differential ringing signal is trapezoidal or sinusoidal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.